Which of these processes in living systems illustrates the Law of Conservation of Energy? A) Cellular respiration and combustion. B) Cellular respiration and photosynthesis. C) Combustion and decomposition. D) Combustion and photosynthesis.

B) Cellular respiration and photosynthesis.

Cellular respiration and photosynthesis are two processes in living systems that illustrate the Law of Conservation of Energy, which states that energy cannot be created or destroyed, but can only be transferred or changed from one form to another.

During photosynthesis, plants convert light energy into chemical energy stored in glucose. This process transforms the energy from sunlight into a usable form of energy for the plant and for other organisms that eat the plants. During cellular respiration, organisms, including plants and animals, convert the chemical energy in glucose into a usable form of energy known as ATP (adenosine triphosphate). While energy changes forms during these processes, the total amount of energy remains constant, following the Law of Conservation of Energy.